Development of In Situ Permeability Test Using Constant Discharge Method for Sandy Soils

Authors: A. Rifa’i, Y. Takeshita, M. Komatsu

Abstract:

The post-rain puddles problem that occurs in the first yard of Prambanan Temple are often disturbing visitor activity. A poodle layer and a drainage system had ever built to avoid such a problem, but puddles still did not stop appearing after rain. Permeability parameter needs to be determined by using a simpler procedure to find exact method of solution. The instrument modelling was proposed according to the development of field permeability testing instrument. This experiment used a proposed Constant Discharge method. Constant Discharge method used a tube poured with constant water flow from unsaturated until saturated soil condition. Volumetric water content (θ) were monitored by soil moisture measurement device. The results were correlations between k and θ which were drawn by numerical approach from Van Genutchen model. Parameters θr optimum value obtained from the test was at very dry soil. Coefficient of permeability with a density of 19.8 kN/m3 for unsaturated conditions was in range of 3 x 10-6 cm/sec (Sr=68%) until 9.98 x 10-4 cm/sec (Sr=82%). The equipment and testing procedure developed in this research was quite effective, simple and easy to be implemented on determining field soil permeability coefficient value of sandy soil. Using constant discharge method in proposed permeability test, value of permeability coefficient under unsaturated condition can be obtained without establish soil water characteristic curve.

Keywords: Constant discharge method, in situ permeability test, sandy soil, unsaturated conditions.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1110199

References:

[1] Hvorslev, M.J., Time Lag and Soil Permeabiity in Ground Water Observation. Waterways Experiment Station, 1951.
[2] Richards, L.A., Capillary Conduction of Liquids Through Porous Mediums. Physics, 1(5), p.318, 1931.
[3] Sunjoto, S., Optimasi Sumur Resapan Sebagai Salah Satu Pencegahan Intrusi Air Laut. In Seminar PAU-IT-UGM. Yogyakarta, 1988.
[4] Takeshita, Y. & Komatsu, M., Field techniques for measuring field saturated and unsaturated hydraulic conductivity using soil moisture profile in a final disposal site, 2012.
[5] Van Genutchen, M.T., A Closed-form Equation for Predicting Hydraulic Conductivity of Unsaturated Soils. Soil Science Society of America Journal, 44, pp.892-98, 1980.